In general, an airbag system is a safety device for an occupant which allows an airbag to be deployed between an occupant and a vehicle structure at the time of a vehicle collision so as to prevent the occupant from directly colliding with the vehicle structure and minimize injury to the occupant.
The airbag system is installed at each region in the vehicle as necessary, and a driver seat airbag device which is mounted in a steering wheel in order to protect an upper body and a head of the occupant seated on a driver seat at the time of a frontal collision, an passenger set airbag device which is mounted at an upper side of a glove box so as to protect the occupant seated on a passenger seat, and a curtain airbag device which is mounted in a side of the vehicle in order to protect the occupant while being deployed between the occupant and a door at the time of a broadside collision are being used.
The curtain airbag is installed along a roof rail of a vehicle so as to protect the occupant while being deployed at the time of a broadside collision or an overturn accident after a broadside collision.
The curtain airbag device uses a steel pipe or a diffuser pocket in order to supply gas produced by the inflator to an airbag cushion, but there are problems in that a design of pattern of the steel pipe is important for leading gas immediately downward from the pipe because gas flows over front and rear sides, and the steel pipe is heavy and expensive.
Because the diffuser pocket is formed by folding a predetermined fabric and sewing outer edges of the diffuser pocket, there is a problem in that a sewed portion of the diffuser pocket is damaged due to high-temperature and high-pressure gas injected from an inflator. Particularly, because a lower side of a portion of the diffuser pocket into which a tip portion of the inflator is inserted is sewed, there are problems in that thermal damage occurs through a sewed gap, and the airbag cushion is also damaged.